The last two decades have been a Golden Age for astronomy. A score of giant new telescopes has started scanning the skies, helping astronomers answer some old questions, and ask a lot more new ones. With these instruments, astronomers have studied dark matter and dark energy; discovered or confirmed hundreds of planets in other star systems; and even watched the weather on the outer planets of our own solar system.

Yet an even brighter age may be ahead, as astronomers prepare the next generation of giant telescopes. One of the biggest is GMT — the Giant Magellan Telescope. It’s being planned and built by a consortium of universities, including the University of Texas at Austin.

The telescope’s primary mirror, which gathers starlight, will consist of seven individual segments, each of which is as big as the largest single mirrors made so far; more about that tomorrow. Combined, the mirrors will give GMT five times the area of the largest telescopes in use today. And the telescope will be built on a mountaintop in Chile, in one of the driest climates on Earth — a perfect spot for skywatching.

With GMT, astronomers expect to not just find planets in other systems, but actually see them. They’ll also use the telescope to look at the dawn of the universe, allowing them to see the formation of the first galaxies. And they’ll make discoveries that today they can’t even predict — part of the age of jumbo telescopes.